Resize PDF pages to A4 or Letter

A4 measures 210 × 297 mm. US Letter measures 215.9 × 279.4 mm (8.5 × 11 inches). Scaling between them can leave extra white space on two edges because the proportions differ. Landscape swaps the width and height. A 10 mm margin reserves at least 10 mm on each edge; existing white space inside the source page remains too.

The visible area of each source page is centered inside the new paper size. Text and vector graphics are embedded as PDF content rather than rendered into images, so selectable text remains selectable. Images scale with the page; enlarging a small scan does not add detail. Mixed-size documents use the same output size, with each page fitted individually. This changes physical page dimensions, not a target file size in KB.

This first version supports static PDFs with standard page boxes and quarter-turn rotation. PDFs containing forms, annotations (including links and signatures), bookmarks, tagged accessibility structure, layers, page transparency groups, document color profiles, attachments or document actions are blocked before export because these features cannot be preserved. Password-protected PDFs must be unlocked first. The preview shows only page 1, so check other pages after downloading. Source metadata is not copied to the new document. Files are limited to 80 MB; the page limit is 200 on phones and low-memory devices, or 500 on larger devices.